[dkfellows]

The processor cores in SpiNNaker run at 200MHz (yes, this is slow!), and can usually issue one instruction per CPU cycle (that's quite nice). However, the trick to getting lots of neurons in is in keeping the number of CPU cycles per synapse event down, since there's a lot more of those than there are neurons.

Yes, bits of the synapse processing code are in assembly coded to waste not one cycle at all. It turns out to be vital to do that in order to keep the efficiency high (and that has many key knock on effects; the synaptic density is a critical parameter for overall model scaling).

In any case, to say that neurons process information at 200Hz is wrong. Or rather it is not even wrong. The individual neurons don't really do very much, but the overall network does a lot and it isn't limited to 200Hz at all. It's just that it handles time in a totally different way to conventional computers...